Method for disposal of liquid waste

ABSTRACT

Disposal apparatus for burning liquid fuel waste comprises a vaporizing surface disposed below a combustion zone and adapted to receive the liquid fuel. The vaporizing surface can be a movable channel extending outside of the apparatus. In operation, the fuel is introduced into the apparatus in liquid form and then vaporized and burned.

United States Patent Hummell METHOD FOR DISPOSAL OF LIQUID WASTE Inventor: John D. Hummell, Brice, Ohio PPG Industries, Inc., Pittsburgh, Pa.

Filed: June 28, 1973 Appl. No.: 374,710

Related US. Application Data Division of Ser. No. 145,342, May 20, 1971, Pat. No. 3,748,081, which is a continuation-in-part of Ser. No. 19,833, March 16, 1970, abandoned.

Assignee:

US. Cl. 431/11, 110/7 S, 431/214,

Int. Cl. F23d 1l/44 Field of Search 110/7 R, 8 R, 9 R, 7 S; 431/211, 8, 37, 190, 214, 242, 285, 336,

337, DIG. 70

References Cited UNITED STATES PATENTS 8/1927 Val Jean 431/10 Sept. 10, 1974 McDonnell 431/238 Bauer 431/285 X Komline.... 34/218 X Wales, Jr. 431/D1G. 70 Hershey et a1 431/337 Bull et al 110/44 R X Somhegyi et a1. 431/8 Primary Examiner-William F. ODea Assistant Examiner-William C. Anderson Attorney, Agent, or Firm-Carl T. Severini ABSTRACT Disposal apparatus for burning liquid fuel waste comprises a vaporizing surface disposed below a combustion zone and adapted to receive the liquid fuel. The

vaporizing surface can be a movable channel extending outside of the apparatus. In operation, the fuel is introduced into the apparatus in liquid form and then vaporized and burned.

17 Claims, 8 Drawing Figures PAIENIED Sm mam SHEU 1 [IF 4 :24 fag FIG].

amass PATIMEB a 0M SHEEH 2 M Q METHOD FOR DISPOSAL OF LIQUID WASTE CROSS-REFERENCE TO RELATED APPLICATIONS This application is a division of copending application Ser. No. 145,342, filed May 20, 1971 (and now US. Pat. No. 3,748,081), which is a continuation-inpart of application Ser. No. 19,833, filed Mar. 16, 1970, and now abandoned.

DESCRIPTION OF THE INVENTION The present invention relates generally to liquid waste disposal systems and particularly to an improved method and apparatus which requires substantially no pre-treatment of the liquid waste before introduction into the incinerator and which results in essentially solids-free exhaust gases, so that no elaborate air pollution control equipment need be associated with the exhaust gases to move particulate matter. The invention is adapted to efficiently dispose of combustible liquid wastes of various types, particularly liquid organic wastes containing solvents, resins, paint sludges, chemical residues, or the like. It is useful with essentially any liquid containing appreciable proportions of combustible organic materials, including aqueous wastes containing up to 70 percent or more of water.

The method of the present invention permits the introduction of liquid waste at ambient temperatures and at a pressure not substantially higher than atmospheric pressure into a combustion chamber. The waste liquid flows freely, without atomization and generally at a metered rate, into the apparatus where it vaporizes and is then mixed with a proper proportion of combustion air to ensure substantially complete smoke-free combustion. With liquid wastes which contain a relatively large percentage of non-combustibles, a further step is desirable where the non-combustible solids in the liquid waste are collected on the vaporizing surface and periodically removed therefrom to prevent excessive buildup and the possibility of the solif particles being picked up and blown out with the exhaust gases.

In general, the apparatus for practicing the novel method of the present invention comprises a housing which defines a chamber having a combustion zone which includes means for introducing air, these usually including a plurality of air inlet ports and an exhaust port. The air inlet ports communicate with a source of combustion air. The lower portion of the chamber is provided with fuel inlet passage means which communicate with a source of liquid waste fuel and which may include means for shielding the incoming fuel from the heat generated in the combustion chamber. The fuel enters below the combustion zone into the lower portion of the chamber, which serves as a vaporizing zone.

The apparatus also includes a vaporizing surface or hearth disposed below the fuel inlet passage means for receivingthe flow of liquid fuel and forming a thin layer thereof, and for vaporization of the volatile combustibles contained therein. An auxiliary burner is disposed in the chamber adjacent to the vaporizing surface for initial heating of the vaporizing surface, if needed, and for initial ignition of the combustibles vaporized from said hearth.

Anothe preferred embodiment of the present invention includes a movable vaporizing surface and means for removing any solids collecting on the surface, .as when the waste contains inorganic materials.

It is therefore an object of the present invention to provide a method of liquid waste disposal and an appa-- ratus for practicing the same which permits liquid fuel wastes to be burned in a simple, efficient manner and which substantially eliminates solids from being introduced into the surrounding atmosphere with the exhaust gases.

It is another object of the present invention to provide a method and apparatus of the typedescribed which permits the liquid wastes to be introduced without pre-heating or high pressure pumping or the like to condition the liquid for intimate mixing with combustion air.

It is another object of the present invention to provide a method and apparatus of the type described which provides for removal of any solids after the volatile constituents have been burned, in a relatively simple manner without polluting the surrounding atmosphere or employing conventional expensive air pollution control equipment.

It is a further object of the present invention to provide a method and apparatus of the type described which is of relatively simple, inexpensive construction and still very efficient. and economical in operation with a minimum of maintenance required.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred embodiments of the invention are clearly shown.

IN THE DRAWINGS FIG. 1 is a top plan view in section of a liquid waste incinerator in accordance with the present invention, the section being taken through one of the air inlet ports;

FIG. 2 is a front elevational view in section of the incinerator shown in FIG. 1, the section being taken along the centerline of the apparatus;

FIG. 3 is a top plan view in section of another preferred embodiment of a liquid waste incinerator constructed in accordance with the present invention, the section being taken along line 44 in FIG. 4;

FIG. 4 is a front elevational view in section of the incinerator shown in FIG. 3, the section being taken along line 33 in FIG. 3;

FIG. 5 is a partial front elevational view in section illustrating the fuel inlet port and the air sea] which comprises a portion of the incinerator shown in FIG. 3;

FIG. 6 is a partial front elevational view in section illustrating a hearth cleaning station which comprises a portion of the apparatus shown in FIG. 3;

FIG. 7 is a partial front elevational view of an idler assembly as shown in FIG. 3, and

FIG. 8 is a partial front elevational view of the drive assembly shown in FIG. 3.

Referring specifically to the drawings, an apparatus for the disposal of liquid wastes constructed in accordance with the present invention is shown in FIGS. 1 and 2 and includes a housing, indicated generally at 20, which forms a chamber 22 having an upper combustion zone 25 generally defined by the upper portion of housing 20.

A plurality of air inlet ports 24 are provided in the side walls of housing 20, in the combustion zone, and

are communicated via air duct 28 to a regulated source of combustion air, such as a conventional blower diagrammatically illustrated at 26.

A pair of fuel inlet passage means 30 are provided in the lower portion of housing and are communicated via pipe lines 34 and valve means 36 to a conventional pump 38 which in turn is communicated with a storage tank or source of liquid wastes, not shown.

Pump 38 and valve means 36 mainly function to meter the flow of liquid wastes into the incinerator as the liquid wastes are not required to be pre-heated nor are high pumping pressures required.

The dimensions of inlet passages although not critical are relatively large as compared to restricted orifices or the like which function to diivide the inlet fluid into a spray as employed in prior liquid waste disposal apparatus.

Generally substantially all liquid wastes commonly incurred could function with merely a gravity feed and pump 38 is used primarily to control the flow rate of liquid entering the housing.

Inlet passages 30 are preferably protected from the heat generated in the combustion chamber by a surrounding insulating material 40 to maintain the temperature of passages 30 low enough to prevent reaction of any of the materials or premature vaporization of the volatile constituents in the liquid waste being fed into housing 20. Suitable insulating materials include water, air, ceramics, etc.

Fuel ignition means, such as auxiliary burner 42, is provided adjacent to the vaporizing surface 44, which is in the bottom portion of chamber 22. The vaporizing surface is usually the bottom of the housing along with the lowermost portion of the sidewalls. This area of the chamber 20, having the fuel inlets and the vaporizing surface, forms vaporizing zone 27.

Vaporizing surface 44 is preferably heated initially by burner 42 to cause an increased rate of vaporization of the volatile constituents present in the thin liquid layer of fuel on the vaporizing surface. The combustible vapors are then ignited by the burner 42 as they become mixed with the combustion air entering inlet ports 24. This permits rapid and smoke-free start-up even with liquid waste fuels having relatively low volatility. After the start of the operation, the heat generated in the upper portion of housing 20 by the burning fuels and radiated down to the surface of the liquid waste and the vaporizing surface is generally sufficient to provide rapid enough vaporization of the volatile constituents to maintain efficient smoke-free combustion. Then auxiliary burner 42 is no longer needed.

The above described arrangement provides ease of control because only a small volumen of liquid fuel is present on the vaporizing surface at any time. This also permits the vaporizing surface to be heated by radiant energy, so as to provide a rapid rate of vaporization of the volatile constituents in the waste fuel, to obtain a maximum rate of complete combustion of the combustible constituents, but not so rapid as to cause any solids that might be suspended in the liquid waste to be carried out with the exhaust vapors. The heat energy supplied to the vaporizing surface should not be sufficient to cause substantial film boiling of the liquid wherein a thin layer of vapor actually forms between the hot vaporizing surface and the liquid being introduced. This is particularly true when the waste fuel contains appreciable solids. However nucleate boiling of the liquid layer is desirable wherein the liquid layer actually lies on the vaporizing surface and the vapors bubble through the liquid to escape and any solids suspended in the liquid remain on the vaporizing surface.

The liquid waste is usually metered into the chamber through passages 30 at a rate consistent with the combustion air flow, which may be regulated with conventional controls, and the burning capacity of the structure. The volatile constituents vaporize in the vaporizing zone and burn in the combustion zone where by appropriate arrangement of the air pattern and control of the fuel vaporization, as described above, the air-vapor mixture is maintained in the proper proportions to provide continuous smoke-free combustion. The mixture within the chamber ranges from vapor-rich in the vaporizing zone, near vaporizing surface 44, to ideal combustion proportions near air ports 24, to air-rich near the exhaust outlet or flue 23.

Now referring to FIGS. 38, another embodiment of the present invention is illustrated, which differs from the first described embodiment mainly in the provision of a movable vaporizing surface for continuously removing the solid residue collecting thereon from a liquid waste bearing a substantial percentage of solids, such as for example, various types of paint sludges.

Referring specifically to FIGS. 3 and 4, a housing, generally indicated at 50, forms a combustion zone 52 generally defined in the upper portion of chamber 51. A plurality of air inlet ports 54 are provided in the combustion zone and are communicated to a regulated source of combustion air, such as for example, a conventional blower diagrammatically illustrated at 56, via duct 58 similarly to the embodiment shown in FIGS. 1 and 2.

The lower portion of chamber 51 is the vaporizing zone 53, and in this area a movable vaporizing surface in the form of a rotating circular channel 60 is provided. A portion of this channel extends through side wall openings 62; the portion of channel 60 extending through housing 50 is disposed in the lower portion or vaporizing zone of chamber 51, below air inlet ports 54 and above auxiliary burner 64. Alternatively, burner 64 can be located above channel 60.

Channel 60 may be driven by any conventional drive means, and is shown by way of example as supported on roller-like rotatable friction drive gear assembly, indicated generally at 70.

Each drive assembly is illustrated by FIG. 8 and includes a supporting base 68 for a plurality of rods 69 which in turn are connected to bearing members 71. A shaft 73 is rotatably mounted in bearing members 71 and operatively connected to a conventional hydraulic drive motor 75. A pair of drive gears 77 and 79 are mounted on shaft 73 and frictionally engage the bottom surface of channel 60. The inner gear 77 is of smaller dimensions than the outer gear 79 since the inner portion of channel 60 will travel a lesser distance than the outer portion.

A pair of idler assemblies, indicated generally at 81, are included to aid in maintaining channel 60 in the same horizontal plane of travel. FIG. 7 illustrates such an idler assembly, each of which includes a support base 83, to which a frame is fixedly mounted by means of rods 87. A pair of shafts 89 are mounted in brackets 91 which are mounted on frame 85. An idler gear 93 is rotatably mounted on each shaft 89 and engages the sides of channel 60.

Any suitable conventional controls may be employed for controlling the rate of rotation of channel 60. It is important to point out that other forms of movable vaporizing surface may be employed without departing from the spirit of the present invention.

The liquid waste is preferably metered to the moving vaporizing surface through an inlet passage and air seal illustrated in FIG. 5. Inlet means in the form of an open pipe 72 is disposed adjacent to one of the side wall opening 62 on the outside of housing 50, and forms a liquid layer on the vaporizing surface (channel 60). As the liquid waste enters the chamber 51, it vaporizes at a relatively rapid rate due first to the heated surface of the channel 60, which is heated initially by auxiliary burner 64, if necessary, and then by the heat radiated from the burning fuel in chamber 51 after initial ignition of the combustible vapors.

Pipe 72 communicates with a source of liquid waste, not shown, and the flow is controlled by a conventional valve means 74 and a conventional pump, not shown, which meters the flow at low pressure into pipe 72.

An air seal 76 with regulated purge air supplied through a pipe 78 which may be connected to blower 56, if desired, surrounds inlet pipe 72 and functions to prevent a back flow of vapors or liquids from inside chamber 51 through side wall opening 62. Air seal 76 includes a housing 100 fixed to the side wall of housing 50 and side wall opening 99 to permit the passage of channel 60. A similarly constructed air seal 82 without an inlet pipe 72, is provided for the other side wall opening 62.

As the volatile constituents in the liquid waste vaporize from that portion of channel 60 inside chamber 51, any solids suspended in the waste remain in channel 60 are carried out of the chamber as the channel rotates. A typical rate of rotation for channel 60 with most materials varies from about 0.5 to about three revolutions per minute.

The solid residue is removed in a continuous manner at a cleaning station indicated generally at 84. Many means for continuously removing the solid residue from channel 60 may be employed without departing from the spirit of the present invention. However, by way of illustration, a typical example is shown in FIG. 6 an includes a housing 86 provided with side wall openings 88 to permit channel 60 to pass through housing 86.

A rotating brush 90 is mounted in housing 86 to contact the surface of channel 60 and may be driven by any conventional means to loosen any solid particles carried on the channel and sweep them towards a collector 92. Collector 92 can be, for example, the inlet portion of a vacuum dust collection system. The solids are thereby pneumatically conveyed to a storage vessel or the like, not shown, for independent disposal.

Basically, the two embodiments described operate in similar manner. The liquid waste is introduced into the vaporizing zone within the chamber, usually by metering at low pressure through an open pipe or the like. The vaporizing surface is preferably pre-heated to ensure rapid smoke-free start-up by vaporizing the volatile constituents rapidly for intimate mixing with combustion air, which is fed through inlet ports disposed above the vaporizing zone and regulated to provide the proper vaporair mixture to ensure continuous complete smoke-free combustion.

In one example of operation of the apparatus of this invention, there is employed apparatus, as illustrated in FIGS. 1 and 2 herein, with refractory-lined chamber 4 /2 feet square and 12 feet high. The fuel inlet passages are two onehalf inch diameter pipes, through which liquid waste fuel is introduced. The exhaust gases are vented through a breeching and stack.

The liquid fuel is organic solvent, mainly aliphatic and aromatic hydrocarbons, containing about 20-25 percent dissolved organic solids and 15-20 percent suspended organic solids.

To initiate operation, an auxiliary burner is fired at about 3,000,000 Btu per hour for about 4 hours to preheat the refractories to a temperature of 1600l800F. The liquid fuel is then fed at a rate of up to gal./hr., which combustion air is introduced from the blowers at 6,000 to 8,000 cubic feet per minute. After the liquid fuel ignites the auxiliary burner is turned off.

Stable, self-sustaining and virtually complete combustion is achieved in this manner, with no flames visible in the stack and fully transparent exhaust gases. The rate of liquid fuel feed is varied (depending on heating value and viscosity) so as to maintain the temperature of the combustion gases entering the stack at the desired temperature, usually between 1,700 and 2,000F., while maintaining the flow of combustion air constant. In other modes of operation the rate of flow of air is also varied.

Operation of the apparatus illustrated in FIGS. 3 and 4 is carried out similarly. The major difference in operation between the two embodiments lies in the movable vaporizing surface which is moved at a controlled rate (for example, about one revolution per minute). Any solid residue collected on the hearth is continuously rremoved at a cleaning station located outside the housing as the volatiles in the liquid waste are continuously burned in the combustion chamber.

An optional component which can be incorporated into the apparatus as described comprises means for recovering heat from the exhaust gases. A conventional heat exchanger or boiler is effectively employedfor this purpose, and not only provides economic advantages but also reduces emission of heat to the atmosphere, i.e., so-called thermal pollution." Other optional equipment can include scrubbers or the like to remove undesirable gases from the exhaust stream.

From the foregoing description it should be readily apparent that the method and apparatus of the present invention provide a simple, efficient systemfor burning liquid waste materials. By vaporizing the volatile constituents in the vaporizing zone, intimate mixing with the combustion air is achieved without the need for high pressure pumping of the inlet fuel to transform the incoming liquid into spray. Also solids which may be suspended in the liquid waste are left on the hearth to prevent them from being entrained in the exhaust gases and carried into the atmosphere. In prior methods wherein the liquid feed is atomized under high pressure, non-combustible solids can be carried off with the exhaust vapors to contribute to air pollution unless the exhaust is associated with relatively complicated and expensive air pollution control apparatus.

While the forms of embodiments of the present invention as herein disclosed constitutes preferred forms,

7 it is to be understood that other forms might be adopted.

I claim:

1. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of components which form a solid residue, which comprises the steps of:

introducing the liquid waste onto a vaporizing surface adapted to be moved into, through and out of a combustion chamber;

moving said vaporizing surface through said combustion chamber, said vaporizing surface having the waste liquid thereon;

maintaining said vaporizing surface while in said combustion chamber, at a temperature at which the volatile components of the liquid waste vaporize, thereby forming a solid residue on said vaporizing surface;

introducing combustion air into said combustion chamber at a location in the path of movement of said vaporized volatile components;

mixing said combustion air and said vaporized volatile components until an intimate mixture thereof is obtained;

controlling the rate of introduction of said volatile components and said air into said combustion chamber such that said intimate mixture of air and volatile components will support continuous, complete, smoke free combustion; and

moving said vaporizing surface out of said combustion chamber and removing said solid residue from said vaporizing surface at a location outside of said combustion chamber.

2. The method of claim 1, wherein said vaporizing surface is moved into, through and out of said combustion chamber in a continuous manner.

3. The method of claim 1, wherein said solid residue is removed from said vaporizing surface in a continuous manner.

4. The method of claim 1, wherein the liquid waste is introduced onto said vaporizing surface in a continuous manner.

5. The method of claim 4, wherein the liquid waste is introduced onto said vaporizing surface at a location outside of said combustion chamber.

6. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of non-volatile components which form a solid residue, which comprises the steps of:

continuously introducing a stream of the liquid waste onto a movable vaporizing surface; continuously advancing the said vaporizing surface through a combustion chamber, said vaporizing surface having the waste liquid thereon;

maintaining the temperature of said vaporizing surface such that the volatile components of the liquid waste vaporize within said combustion chamber, thereby forming a solid residue on the advancing vaporizing surface;

introducing combustion air into said combustion chamber at a location in the path of movement of said vaporized volatile components;

mixing said combustion air and said vaporized volatile components until an intimate mixture thereof is obtained;

controlling the rate of introduction of said volatile components and said air into saiid combustion chamber such that said intimate mixture of air and volatile components will support continuous, complete, smoke free combustion; and continuously removing said solid residue from said vaporizing surface at a location outside of said combustion chamber. 7. The method of claim 6, further comprising the step of sealing said combustion chamber to preclude the escape of said volatile components of said liquid waste.

8. The method of claim 6, wherein said vaporizing surface comprises a circular channel which is disposed partly in said combustion chamber, and which is rotated continuously relative to said chamber.

9. The method of claim 8, wherein the step of removing said solid residue from said vaporizing surface comprises contacting the continuously advancing vaporizing surface with a rotating brush to loosen said residue, and collecting the loosen residue.

10. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of a component which forms a solid residue, which comprises the steps of:

introducing the liquid waste onto a vaporizing surface adapted to be moved into, through and out of a combustion chamber;

moving said vaporizing surface having the liquid waste thereon through said combustion chamber;

maintaining said vaporizing surface, while in said combustion chamber, at a temperature at which the volatile components of the liquid waste vaporize, thereby forming a solid residue on said vaporizing surface;

introducing combustion air into said combustion chamber at a location in the path of said vaporized volatile components;

controlling the ratio of said volatile components and said air in said combustion chamber so as to provide proportioned amounts thereof sufficient to maintain a combustible vapor-air mixture and provide continuous complete smoke free combustion;

moving said vaporizing surface out of said combustion chamber and removing said solid residue from said vaporizing surface at a location outside of said combustion chamber.

11. The method of claim 10, wherein said vaporizing surface is moved into, through and out of said combustion chamber in a continuous manner.

12. The method of claim 10, wherein said solid residue is removed from said vaporizing surface in a continuous manner.

13. The method of claim 10, wherein the liquid waste is introduced onto said vaporizing surface in a continuous manner.

14. The method of claim 13, wherein the liquid waste is introduced onto said vaporizing surface at a location outside of said combustion chamber.

15. The method of claim 13, further comprising the step of sealing said combustion chamber to preclude the escape of said volatile components of said liquid waste.

moving said solid residue from said vaporizing surface comprises contacting the continuously advancing vaporizing surface with a rotating brush to loosen said residue, and collecting the loosen residue. 

1. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of components which form a solid residue, which comprises the steps of: introducing the liquid waste onto a vaporizing surface adapted to be moved into, through and out of a combustion chamber; moving said vaporizing surface through said combustion chamber, said vaporizing surface having the waste liquid thereon; maintaining said vaporizing surface while in said combustion chamber, at a temperature at which the volatile components of the liquid waste vaporize, thereby forming a solid residue on said vaporizing surface; introducing combustion air into said combustion chamber at a location in the path of movement of said vaporized volatile components; mixing said combustion air and said vaporized volatile components until an intimate mixture thereof is obtained; controlling the rate of introduction of said volatile components and said air into said combustion chamber such that said intimate mixture of air and volatile components will support continuous, complete, smoke free combustion; and moving said vaporizing surface out of said combustion chamber and removing said solid residue from said vaporizing surface at a location outside of said combustion chamber.
 2. The method of claim 1, wherein said vaporizing surface is moved into, through and out of said combustion chamber in a continuous manner.
 3. The method of claim 1, wherein said solid residue is removed from said vaporizing surface in a continuous manner.
 4. The method of claim 1, wherein the liquid waste is introduced onto said vaporizing surface in a continuous manner.
 5. The method of claim 4, wherein the liquid waste is introduced onto said vaporizing surface at a location outside of said combustion chamber.
 6. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of non-volatile components which form a solid residue, which comprises the steps of: continuously introducing a stream of the liquid waste onto a movable vaporizing surface; continuously advancing the said vaporizing surface through a combustion chamber, said vaporizing surface having the waste liquid thereon; maintaining the temperature of said vaporizing surface such that the volatile components of the liquid waste vaporize within said combustion chamber, thereby forming a solid residue on the advancing vaporizing surface; introducing comBustion air into said combustion chamber at a location in the path of movement of said vaporized volatile components; mixing said combustion air and said vaporized volatile components until an intimate mixture thereof is obtained; controlling the rate of introduction of said volatile components and said air into saiid combustion chamber such that said intimate mixture of air and volatile components will support continuous, complete, smoke free combustion; and continuously removing said solid residue from said vaporizing surface at a location outside of said combustion chamber.
 7. The method of claim 6, further comprising the step of sealing said combustion chamber to preclude the escape of said volatile components of said liquid waste.
 8. The method of claim 6, wherein said vaporizing surface comprises a circular channel which is disposed partly in said combustion chamber, and which is rotated continuously relative to said chamber.
 9. The method of claim 8, wherein the step of removing said solid residue from said vaporizing surface comprises contacting the continuously advancing vaporizing surface with a rotating brush to loosen said residue, and collecting the loosen residue.
 10. A method of disposing of liquid wastes which contain at least a substantial portion of volatile components and at least a minor portion of a component which forms a solid residue, which comprises the steps of: introducing the liquid waste onto a vaporizing surface adapted to be moved into, through and out of a combustion chamber; moving said vaporizing surface having the liquid waste thereon through said combustion chamber; maintaining said vaporizing surface, while in said combustion chamber, at a temperature at which the volatile components of the liquid waste vaporize, thereby forming a solid residue on said vaporizing surface; introducing combustion air into said combustion chamber at a location in the path of said vaporized volatile components; controlling the ratio of said volatile components and said air in said combustion chamber so as to provide proportioned amounts thereof sufficient to maintain a combustible vapor-air mixture and provide continuous complete smoke free combustion; moving said vaporizing surface out of said combustion chamber and removing said solid residue from said vaporizing surface at a location outside of said combustion chamber.
 11. The method of claim 10, wherein said vaporizing surface is moved into, through and out of said combustion chamber in a continuous manner.
 12. The method of claim 10, wherein said solid residue is removed from said vaporizing surface in a continuous manner.
 13. The method of claim 10, wherein the liquid waste is introduced onto said vaporizing surface in a continuous manner.
 14. The method of claim 13, wherein the liquid waste is introduced onto said vaporizing surface at a location outside of said combustion chamber.
 15. The method of claim 13, further comprising the step of sealing said combustion chamber to preclude the escape of said volatile components of said liquid waste.
 16. The method of claim 13, wherein said vaporizing surface comprises a circular channel which is disposed partly in said combustion chamber, and which is rotated continuously relative to said chamber.
 17. The method of claim 16, wherein the step of removing said solid residue from said vaporizing surface comprises contacting the continuously advancing vaporizing surface with a rotating brush to loosen said residue, and collecting the loosen residue. 